//
// Created by 123 on 2025/1/7.
//
#include "vector"
#include "algorithm"
#include "iostream"
#include "string"
using namespace std;

void test1(){
    vector<vector<int>> v;
    vector<int> v1;
    vector<int> v2;
    vector<int> v3;
    for (int i = 0; i < 4; ++i) {
        v1.push_back(i+1);
        v2.push_back(i+2);
        v3.push_back(i+3);
    }
    v.push_back(v1);
    v.push_back(v2);
    v.push_back(v3);
    for(vector<vector<int>>::iterator it=v.begin();it != v.end();it++){
        for(vector<int>::iterator vit=(*it).begin();vit != it->end();vit++){
            cout << *vit << " ";
        }
        cout << endl;
    }
}


int main111(){
    test1();
    return 0;
}